Building CapaCITY/É for sustainable transportation: protocol for an implementation science research program in healthy cities.

INTRODUCTION: Improving sustainable transportation options will help cities tackle growing challenges related to population health, congestion, climate change and inequity. Interventions supporting active transportation face many practical and political hurdles. Implementation science aims to understand how interventions or policies arise, how they can be translated to new contexts or scales and who benefits. Sustainable transportation interventions are complex, and existing implementation science frameworks may not be suitable. To apply and adapt implementation science for healthy cities, we have launched our mixed-methods research programme, CapaCITY/É. We aim to understand how, why and for whom sustainable transportation interventions are successful and when they are not. METHODS AND ANALYSIS: Across nine Canadian municipalities and the State of Victoria (Australia), our research will focus on two types of sustainable transportation interventions: all ages and abilities bicycle networks and motor vehicle speed management interventions. We will (1) document the implementation process and outcomes of both types of sustainable transportation interventions; (2) examine equity, health and mobility impacts of these interventions; (3) advance implementation science by developing a novel sustainable transportation implementation science framework and (4) develop tools for scaling up and scaling out sustainable transportation interventions. Training activities will develop interdisciplinary scholars and practitioners able to work at the nexus of academia and sustainable cities. ETHICS AND DISSEMINATION: This study received approval from the Simon Fraser University Office of Ethics Research (H22-03469). A Knowledge Mobilization Hub will coordinate dissemination of findings via a website; presentations to academic, community organisations and practitioner audiences; and through peer-reviewed articles.

Risk Factors and Inequities in Transportation Injury and Mortality in the Canadian Census Health and Environment Cohorts (CanCHECs).

BACKGROUND: Road traffic injury contributes substantially to morbidity and mortality. Canada stands out among developed countries in not conducting a national household travel survey, leading to a dearth of national transportation mode data and risk calculations that have appropriate denominators. Since traffic injuries are specific to the mode of travel used, these risk calculations should consider travel mode. METHODS: Census data on mode of commute is one of the few sources of these data for persons aged 15 and over. This study leveraged a national data linkage cohort, the Canadian Census Health and Environment Cohorts, that connects census sociodemographic and commute mode data with records of deaths and hospitalizations, enabling assessment of road traffic injury associations by indicators of mode of travel (commuter mode). We examined longitudinal (1996-2019) bicyclist, pedestrian, and motor vehicle occupant injury and fatality risk in the Canadian Census Health and Environment Cohorts by commuter mode and sociodemographic characteristics using Cox proportional hazards models within the working adult population. RESULTS: We estimated positive associations between commute mode and same mode injury and fatality, particularly for bicycle commuters (hazard ratios for bicycling injury was 9.1 and for bicycling fatality was 11). Low-income populations and Indigenous people had increased injury risk across all modes. CONCLUSIONS: This study shows inequities in transportation injury risk in Canada and underscores the importance of adjusting for mode of travel when examining differences between population groups.

Traditional activities and general and mental health of adult Indigenous peoples living off-reserve in Canada.

Introduction: We examined associations between traditional Indigenous activities and self-perceived general and mental health in adult Indigenous persons living off-reserve in Canada using the 2012 and 2017 Aboriginal Peoples Surveys (APS), the two most recent datasets. We utilized four traditional Indigenous activities including hunting, making clothes or footwear, making arts or crafts, and gathering wild plants to investigate these self-reported data. Methods: Data from 9,430 and 12,598 respondents from the 2012 and 2017 APS, respectively, who responded to 15 questions concerning traditional activities were assessed using multivariable logistic regression to produce odds ratios (OR) and 95% confidence intervals (CI). Covariates included age, sex, education-level, income-level, Indigenous identity, residential school connection, ability to speak an Indigenous language, smoking status, and alcohol consumption frequency. Results: Using the 2012 APS, clothes-making was associated with poor self-reported general (OR = 1.50, 95%CI: 1.12-1.99) and mental (OR = 1.59, 95%CI: 1.14-2.21) health. Hunting was associated with good mental health (OR = 0.71 95%CI: 0.56-0.93). Similarly, 2017 analyses found clothes-making associated with poor general health (OR = 1.25, 95%CI: 1.01-1.54), and hunting associated with good general (OR = 0.76, 95%CI: 0.64-0.89) and mental (OR = 0.69, 95%CI: 0.58-0.81) health. Artmaking was associated with poor general (OR = 1.37, 95%CI: 1.17-1.60) and mental (OR = 1.85, 95%CI: 1.58-2.17) health. Conclusion: Hunting had protective relationships with mental and general health, which may reflect benefits of participation or engagement of healthier individuals in this activity. Clothes-making and artmaking were associated with poor general and poor mental health, possibly representing reverse causation as these activities are often undertaken therapeutically. These findings have implications for future research, programs and policies concerning Indigenous health.

Kidney function testing prior to contrast-enhanced CT: a comparative cost analysis of a personalised risk-stratified pathway versus a test all approach.

AIM: To map current contrast-enhanced computed tomography (CT) pathways, develop a risk-stratified pathway, and model associated costs and resource use. MATERIALS AND METHODS: Phase 1 comprised multicentre mapping of current practice and development of an alternative pathway, replacing pre-assessment of estimated glomerular filtration rate (eGFR) with a scan-day screening questionnaire for risk stratification and point of care (PoC) creatinine. Phase 2 measured resource use and analysis of routinely collected data, used to populate a model comparing the costs of current and risk-stratified pathways in Phase 3. RESULTS: Site variation across a range of processes within the clinical care pathway was identified. Data from a single centre suggested that 78% (n=347/447) could have avoided their pre-scan laboratory test as they did not have post-contrast acute kidney injury (AKI) risk factors. Only 24% of outpatients who underwent computed tomography (CT) would have identified risk factors, which would have prompted a scan-day PoC test. There was a 94% probability that the risk-stratified pathway was cost-saving, with an estimated 5-year potential cost saving of £69,620 (95% CI: -£13,295-£154,603). Although the cost of a laboratory serum creatinine test is cheaper than the PoC equivalent (£5.29 versus £5.96), the screening questionnaire ruled out the need for a large majority of the eGFR measurements specifically for the CT examination. CONCLUSION: The present study proposes an alternative pathway, which has the potential to improve the efficiency of the current CT pathway. A multicentre appraisal is required to demonstrate the impact of embedding this new pathway on a wider NHS level, particularly in light of new diagnostic guidance (DG37) published by NICE.

Age Differences in Work-Disability Duration Across Canada: Examining Variations by Follow-Up Time and Context.

Purpose This study aimed to understand age differences in wage-replacement duration by focusing on variations in the relationship across different periods of follow-up time. Methods We used administrative claims data provided by six workers' compensation systems in Canada. Included were time-loss claims for workers aged 15-80 years with a work-related injury/illness during the 2011 to 2015 period (N = 751,679 claims). Data were coded for comparability across cohorts. Survival analysis examined age-related differences in the hazard of transitioning off (versus remaining on) disability benefits, allowing for relaxed proportionality constraints on the hazard rates over time. Differences were examined on the absolute (hazard difference) and relative (hazard ratios [HR]) scales. Results Older age groups had a lower likelihood of transitioning off wage-replacement benefits compared to younger age groups in the overall models (e.g., 55-64 vs. 15-24 years: HR 0.62). However, absolute and relative differences in age-specific hazard rates varied as a function of follow-up time. The greatest age-related differences were observed at earlier event times and were attenuated towards a null difference across later follow-up event times. Conclusions Our study provides new insight into the workplace injury/illness claim and recovery processes and suggests that older age is not always strongly associated with worse disability duration outcomes. The use of data from multiple jurisdictions lends external validity to our findings and demonstrates the utility of using cross-jurisdictional data extracts. Future work should examine the social and contextual determinants that operate during various recovery phases, and how these factors interact with age.

A profile of Australian mental health carers, their caring role and service needs: results from the 2012 Survey of Disability, Ageing and Carers.

AIMS: Planning mental health carer services requires information about the number of carers, their characteristics, service use and unmet support needs. Available Australian estimates vary widely due to different definitions of mental illness and the types of carers included. This study aimed to provide a detailed profile of Australian mental health carers using a nationally representative household survey. METHODS: The number of mental health carers, characteristics of carers and their care recipients, caring hours and tasks provided, service use and unmet service needs were derived from the national 2012 Survey of Disability, Ageing and Carers. Co-resident carers of adults with a mental illness were compared with those caring for people with physical health and other cognitive/behavioural conditions (e.g., autism, intellectual disability, dementia) on measures of service use, service needs and aspects of their caring role. RESULTS: In 2012, there were 225 421 co-resident carers of adults with mental illness in Australia, representing 1.0% of the population, and an estimated further 103 813 mental health carers not living with their care recipient. The majority of co-resident carers supported one person with mental illness, usually their partner or adult child. Mental health carers were more likely than physical health carers to provide emotional support (68.1% v. 19.7% of carers) and less likely to assist with practical tasks (64.1% v. 86.6%) and activities of daily living (31.9% v. 48.9%). Of co-resident mental health carers, 22.5% or 50 828 people were confirmed primary carers - the person providing the most support to their care recipient. Many primary mental health carers (37.8%) provided more than 40 h of care per week. Only 23.8% of primary mental health carers received government income support for carers and only 34.4% received formal service assistance in their caring role, while 49.0% wanted more support. Significantly more primary mental health than primary physical health carers were dissatisfied with received services (20.0% v. 3.2%), and 35.0% did not know what services were available to them. CONCLUSIONS: Results reveal a sizable number of mental health carers with unmet needs in the Australian community, particularly with respect to financial assistance and respite care, and that these carers are poorly informed about available supports. The prominence of emotional support and their greater dissatisfaction with services indicate a need to better tailor carer services. If implemented carefully, recent Australian reforms including the Carer Gateway and National Disability Insurance Scheme hold promise for improving mental health carer supports.

Characteristics and clinical assessment of antibiotic delivery by chitosan sponge in the high-risk diabetic foot: a case series.

OBJECTIVE: The local delivery of antimicrobials is attractive for a number of reasons. Chitosan, a biodegradable polysaccharide sponge material, has been proposed as medium to deliver antibiotics directly to wounds. In this report we evaluate the safety and practicality of antimicrobial delivery via chitosan sponge. METHOD: We present the clinical course and systemic absorption characteristics of three cases of people with diabetic foot wounds treated with antibiotic soaked chitosan sponge (Sentrex BioSponge, Bionova Medical, Germantown, TN). The antibiotic sponge was made by reconstituting 1.2g tobramycin or 100mg doxycycline in 10-15ml saline and saturating the sponge with the solution. The sponge was then applied to the wounds. Serum levels of each respective antibiotic were evaluated after application. Additional in vitro studies were conducted evaluating elution of antibiotics from the chitosan sponge at established minimum inhibitory concentrations (MIC) for Staphylococcus aureus over 28 days. RESULTS: No patient experienced adverse local or systemic effects due to the sponge treatment. The measured serum levels applied antibiotics remained far less than established minimums after intravenous therapy. Each patient required further treatment, however local infection or contamination resolved during the course of their hospital stay after the chitosan/antibiotic application. CONCLUSION: The use of antibiotic-impregnated chitosan sponges appears a safe and effective mechanism of local delivery of antimicrobials in wounds. Future studies and clinical trials are ongoing to confirm these results and to guide clinical applications.

An assessment of US microbiome research.

Genome-enabled technologies have supported a dramatic increase in our ability to study microbial communities in environments and hosts. Taking stock of previously funded microbiome research can help to identify common themes, under-represented areas and research priorities to consider moving forward. To assess the status of US microbiome research, a team of government scientists conducted an analysis of federally funded microbiome research. Microbiomes were defined as host-, ecosystem- or habitat-associated communities of microorganisms, and microbiome research was defined as those studies that emphasize community-level analyses using 'omics technologies. Single pathogen, single strain and culture-based studies were not included, except symbiosis studies that served as models for more complex communities. Fourteen governmental organizations participated in the data call. The analysis examined three broad research themes, eight environments and eight microbial categories. Human microbiome research was larger than any other environment studied, and the basic biology research theme accounted for half of the total research activities. Computational biology and bioinformatics, reference databases and biorepositories, standardized protocols and high-throughput tools were commonly identified needs. Longitudinal and functional studies and interdisciplinary research were also identified as needs. This study has implications for the funding of future microbiome research, not only in the United States but beyond.

Shift Work and Obesity among Canadian Women: A Cross-Sectional Study Using a Novel Exposure Assessment Tool.

BACKGROUND/OBJECTIVES: It has been suggested that the association between shift work and chronic disease is mediated by an increase in obesity. However, investigations of the relationship between shift work and obesity reveal mixed findings. Using a recently developed exposure assessment tool, this study examined the association between shift work and obesity among Canadian women from two studies: a cohort of university alumni, and a population-based study. METHODS: Self-administered questionnaire data were used from healthy, currently employed females in a population-based study, the Ontario Women's Diet and Health case-control study (n = 1611 controls), and from a subset of a of university alumni from the Canadian Study of Diet, Lifestyle, and Health (n = 1097) cohort study. Overweight was defined as BMI≥25 to <30, and obesity as BMI≥30. Reported occupation was converted to occupational codes and linked to a probability of shift work value derived from Survey of Labour and Income Dynamics data. Regular evenings, nights, or rotating work comprised shift work. Polytomous logistic regression estimated the association between probability of shift work, categorized as near nil, low, medium, and high probability of shift work, on overweight and obesity, controlling for detected confounders. RESULTS: In the population-based sample, high probability of shift work was associated with obesity (reference = near nil probability of shift work, OR: 1.88, 95% CI: 1.01-3.51, p = 0.047). In the alumni cohort, no significant association was detected between shift work and overweight or obesity. CONCLUSIONS: As these analyses found a positive association between high probability of shift work exposure and obesity in a population-based sample, but not in an alumni cohort, it is suggested that the relationship between shift work and obesity is complex, and may be particularly susceptible to occupational and education-related factors within a given population.

Human rights and access to hepatitis C treatment for people who inject drugs.

BACKGROUND: People who inject drugs (PWID) achieve adherence to and outcomes from hepatitis C virus (HCV) treatment comparable to other patients. Nonetheless, this population has been excluded from treatment by regulation or practice. Approval of safer and more effective oral HCV medicines should offer greater treatment options for PWID, although high medicine prices have led to continued treatment rationing and exclusion in developed countries. In middle-income countries (MICS), treatment is largely unavailable and unaffordable for most PWID. METHODS: Human rights analysis, with its emphasis on the universal and interconnected nature of the economic, social and political spheres, offers a useful framework for HCV treatment reform. Using peer-reviewed and grey literature, as well as community case reports, we discuss barriers to treatment, correlate these barriers to rights violations, and highlight examples of community advocacy to increase treatment for PWID. RESULTS: Structural drivers of lack of treatment access for PWID include stigma in health settings; drug use status as a criterion for treatment exclusion; requirements for fees or registration by name as a drug user prior to treatment initiation; and incarceration/detention in prisons and rehabilitation centers where treatment is unavailable. High medicine prices force further exclusion of PWID, with cost containment masked as concern about treatment adherence. These barriers correlate to multiple rights violations, including of the rights to privacy; non-discrimination; health; freedom of information; fair trial; and freedom from cruel, inhuman and degrading treatment. CONCLUSIONS: Needed reforms include decriminalization of drug use, possession of drugs and drug injecting equipment; removal of exclusionary or discriminatory treatment protocols; approaches to strengthen links between health providers and increase participation of PWID in treatment design and implementation; and measures to increase transparency in government/pharmaceutical company negotiations and reduce treatment price.

Challenges to student transition in allied health undergraduate education in the Australian rural and remote context: a synthesis of barriers and enablers.

INTRODUCTION: The optimum supply of an allied health workforce in rural and remote communities is a persistent challenge. Despite previous indicative research and government investment, the primary focus for rural and remote recruitment has been on the medical profession. The consequent shortage of allied health professionals leaves these communities less able to receive appropriate health care. This comprehensive review incorporates a literature analysis while articulating policy and further research implications. METHODS: The objective was to identify drivers to recruitment and retention of an allied health workforce in rural and remote communities. This issue was observed in two parts: identification of barriers and enablers for students accessing allied health undergraduate tertiary education, and barriers and enablers to clinical placement experience in rural and remote communities. A search of empirical literature was conducted together with review of theoretical publications, including public health strategies and policy documents. Database searches of CINAHL, Medline, ERIC, PsychInfo and Scopus were performed. Selection criteria included Australian research in English, full text online, keywords in title or abstract, year of publication 1990 to 2012 and research inclusive of rural and remote context by application of the Australian Standard Geographical Classication (ASGC) Remoteness Structure. Theoretical publications, or grey literature, were identified by broad Google searches utilising a variety of search terms relevant to the review objective. Allied health professions were defined as including audiology, dietetics, occupational therapy, optometry, orthoptics, orthotics and prosthetics, pharmacy, physiotherapy, podiatry, psychology, radiography, social work, speech pathology and Aboriginal and Torres Strait Islander Health Workers. RESULTS: A total of 28 empirical publications met the selection criteria with a further 22 grey literature texts identified with relevance to the research objective. Patterns of barriers and enablers for rural and remote student transition in the allied health professions were identified in the literature. Recruitment pathways to allied health tertiary studies in rural and remote communities are vague and often interrupted, and the return of graduates is haphazard. Students from rural and remote communities face an assembly of barriers. They often experience secondary education disadvantage with inadequate subject choices, pathways and opportunities. Programs designed to facilitate transition to tertiary study are often limited in their capacity to address cumulative concerns. Students also face financial imposts and are confronted by daunting social isolation, and separation from families and support systems. In regard to clinical placement, the disincentives weigh heavily. The financial burdens of a rural placement offer little inducement. Social isolation associated with a placement far from home is more acutely felt by students when there is inadequate administrative support and consequent disillusionment. Students also lack a frame of reference to pursue a rural placement option, and are often discouraged by the cumulative commitments involved. CONCLUSIONS: Clear and accessible pathways to allied health training for students from rural and remote communities are pivotal to a stronger representation of this cohort among graduates. Similarly, greater representation of rural and remote clinical placements for allied health undergraduate students is an important facilitator. Despite regional coordination and strategies designed to promote a broader range of placement opportunities, the problems remain. This review has consequences for policy and program development for growth of the rural allied health workforce in Australia, as well as identifying knowledge deficits to guide future research endeavours.

Does a research article's country of origin affect perception of its quality and relevance? A national trial of US public health researchers.

OBJECTIVES: The source of research may influence one's interpretation of it in either negative or positive ways, however, there are no robust experiments to determine how source impacts on one's judgment of the research article. We determine the impact of source on respondents' assessment of the quality and relevance of selected research abstracts. DESIGN: Web-based survey design using four healthcare research abstracts previously published and included in Cochrane Reviews. SETTING: All Council on the Education of Public Health-accredited Schools and Programmes of Public Health in the USA. PARTICIPANTS: 899 core faculty members (full, associate and assistant professors) INTERVENTION: Each of the four abstracts appeared with a high-income source half of the time, and low-income source half of the time. Participants each reviewed the same four abstracts, but were randomly allocated to receive two abstracts with high-income source, and two abstracts with low-income source, allowing for within-abstract comparison of quality and relevance PRIMARY OUTCOME MEASURES: Within-abstract comparison of participants' rating scores on two measures--strength of the evidence, and likelihood of referral to a peer (1-10 rating scale). OR was calculated using a generalised ordered logit model adjusting for sociodemographic covariates. RESULTS: Participants who received high income country source abstracts were equal in all known characteristics to the participants who received the abstracts with low income country sources. For one of the four abstracts (a randomised, controlled trial of a pharmaceutical intervention), likelihood of referral to a peer was greater if the source was a high income country (OR 1.28, 1.02 to 1.62, p<0.05). CONCLUSIONS: All things being equal, in one of the four abstracts, the respondents were influenced by a high-income source in their rating of research abstracts. More research may be needed to explore how the origin of a research article may lead to stereotype activation and application in research evaluation.

A randomised controlled trial of a consumer-focused e-health strategy for cardiovascular risk management in primary care: the Consumer Navigation of Electronic Cardiovascular Tools (CONNECT) study protocol.

INTRODUCTION: Fewer than half of all people at highest risk of a cardiovascular event are receiving and adhering to best practice recommendations to lower their risk. In this project, we examine the role of an e-health-assisted consumer-focused strategy as a means of overcoming these gaps between evidence and practice. Consumer Navigation of Electronic Cardiovascular Tools (CONNECT) aims to test whether a consumer-focused e-health strategy provided to Aboriginal and Torres Strait Islander and non-indigenous adults, recruited through primary care, at moderate-to-high risk of a cardiovascular disease event will improve risk factor control when compared with usual care. METHODS AND ANALYSIS: Randomised controlled trial of 2000 participants with an average of 18 months of follow-up to evaluate the effectiveness of an integrated consumer-directed e-health portal on cardiovascular risk compared with usual care in patients with cardiovascular disease or who are at moderate-to-high cardiovascular disease risk. The trial will be augmented by formal economic and process evaluations to assess acceptability, equity and cost-effectiveness of the intervention. The intervention group will participate in a consumer-directed e-health strategy for cardiovascular risk management. The programme is electronically integrated with the primary care provider's software and will include interactive smart phone and Internet platforms. The primary outcome is a composite endpoint of the proportion of people meeting the Australian guideline-recommended blood pressure (BP) and cholesterol targets. Secondary outcomes include change in mean BP and fasting cholesterol levels, proportion meeting BP and cholesterol targets separately, self-efficacy, health literacy, self-reported point prevalence abstinence in smoking, body mass index and waist circumference, self-reported physical activity and self-reported medication adherence. ETHICS AND DISSEMINATION: Primary ethics approval was received from the University of Sydney Human Research Ethics Committee and the Aboriginal Health and Medical Research Council. Results will be disseminated via the usual scientific forums including peer-reviewed publications and presentations at international conferences CLINICAL TRIALS REGISTRATION NUMBER: ACTRN12613000715774.

Parkinson's disease and occupation: differences in associations by case identification method suggest referral bias.

METHODS: We used a population-based sample of 403 Parkinson's disease cases and 405 controls to examine risks by occupation. Results were compared to a previous clinic-based analysis. RESULTS: With censoring of jobs held within 10 years of diagnosis, the following had significantly or strongly increased risks: social science, law and library jobs (OR = 1.8); farming and horticulture jobs (OR = 2.0); gas station jobs (OR = 2.6); and welders (OR = 3.0). The following had significantly decreased risks: management and administration jobs (OR = 0.70); and other health care jobs (OR = 0.44). CONCLUSIONS: These results were consistent with other findings for social science and farming occupations. Risks for teaching, medicine and health occupations were not elevated, unlike our previous clinic-based study. This underscores the value of population-based over clinic-based samples. Occupational studies may be particularly susceptible to referral bias because social networks may spread preferentially via jobs.

Assessment of the validity of the English National Health Service Adult In-Patient Survey for use within individual specialties.

BACKGROUND: Healthcare improvement requires rigorous measurement. Patient experience is a key healthcare outcome and target for improvement. Its measurement requires psychometrically validated questionnaires. In England, the Adult In-Patient Survey (AIPS), which is validated for use across the entire acute inpatient population, is administered to unselected patients after discharge from National Health Service acute Trusts. The AIPS is reported at an organisational level, but subhospital level data are needed for local quality improvement; it is currently uncertain whether the AIPS retains validity in local specialty subgroups. METHODS: We analysed the results of AIPS for 2010 (n=56 931 returns) by specialty (medicine, surgery, orthopaedics, renal medicine, neurosurgery, obstetrics-gynaecology and oncology) to determine whether validity is retained at a suborganisational level. RESULTS: Criterion validity and internal consistency of AIPS were retained for most specialty subgroups. When small local samples were excluded, the results for Trust level specialty groups were similar over a 2-year period, indicating test stability. For oncology there was poor internal consistency in the 'doctors' domain and criterion validity, expressed as the relationship elements of experience and overall rating of care, was less than for other specialties. CONCLUSIONS: The AIPS is suitable for use within many specialties, but our findings question some elements of validity for oncology inpatients. We recommend that future surveys are administered and reported by specialty, to inform local improvement and permit comparison of specialty units.

Retrospective assessment of occupational exposure to whole-body vibration for a case-control study.

Occupational whole-body vibration is often studied as a risk factor for conditions that may arise soon after exposure, but only rarely have studies examined associations with conditions arising long after occupational exposure has ceased. We aimed to develop a method of constructing previous occupational whole-body vibration exposure metrics from self-reported data collected for a case-control study of Parkinson's disease. A detailed job history and exposure interview was administered to 808 residents of British Columbia, Canada (403 people with Parkinson's disease and 405 healthy controls). Participants were prompted to report exposure to whole-body vibrating equipment. We limited the data to exposure reports deemed to be above background exposures and used the whole-body vibration literature (typically reporting on seated vector sum measurements) to assign intensity (acceleration) values to each type of equipment reported. We created four metrics of exposure (duration of exposure, most intense equipment exposure, and two dose metrics combining duration and intensity) and examined their distributions and correlations. We tested the role of age and gender in predicting whole-body vibration exposure. Thirty-six percent of participants had at least one previous occupational exposure to whole-body vibrating equipment. Because less than half of participants reported exposure, all continuous metrics exhibited positively skewed distributions, although the distribution of most intense equipment exposure was more symmetrically distributed among the exposed. The arithmetic mean of duration of exposure among those exposed was 14.0 (standard deviation, SD: 14.2) work years, while the geometric mean was 6.8 (geometric SD, GSD: 4.5). The intensity of the most intense equipment exposure (among the exposed) had an arithmetic mean of 0.9 (SD: 0.3) m·s(-2) and a geometric mean of 0.8 (GSD: 1.4). Male gender and older age were both associated with exposure, although the effect of age was attenuated after adjustment for gender. The methods developed allowed us to create continuous metrics of whole-body vibration retrospectively, displaying useful variance for epidemiologic studies.

A reproductive fitness cost associated with Hessian fly (Diptera: Cecidomyiidae) virulence to wheat's H gene-mediated resistance.

We studied whether adaptation of the Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), to plant resistance incurs fitness costs. In this gene-for-gene interaction, adaptation to a single H resistance gene occurs via loss of a single effector encoded by an Avirulence gene. By losing the effector, the adapted larva now survives on the H gene plant, presumably because it evades the plant's H gene-mediated surveillance system. The problem is the Hessian fly larva needs its effectors for colonization. Thus, for adapted individuals, there may be a cost for losing the effector, with this then creating a trade-off between surviving on H-resistant plants and growing on plants that lack H genes. In two different tests, we used wheat lacking H genes to compare the survival and growth of a nonadapted strain to two H-adapted strains. The two adapted strains differed in that one had been selected for adaptation to H9, whereas the other strain had been selected for adaptation to H13. Tests showed that two H-adapted strains were similar to the nonadapted strain in egg-to-adult survival but that they differed in producing adults with smaller wings. By using known relationships between wing length and reproductive potential, we found that losses in wing length underestimate losses in reproductive potential. For example, H9- and H13-adapted females had 9 and 3% wing losses, respectively, but they were estimated to have 32 and 12% losses in egg production. Fitness costs of adaptation will be investigated further via selection experiments comparing Avirulence allele frequencies for Hessian fly populations exposed or not exposed to H genes.